Air compressor



1943- s. E. JEssuP I 2,327,269

AIR COMPRESSOR Filed May 26, 1941 3 Sheets-Sheet 1 lNVENTOR.

Aug. 17, 1943. s. E. JESSUP 2,327,269

I AIR COMPRESSOR Filed May 26, 1941 3 Sheets-Sheet 2 INVENTOR.

SQ'ZZersZ Js 3 up Patented Aug. 17, 1943 UNITED STATES PATENT OFFICE AIRCOIVLPRESSGR Sellers E. Jessup, Les Angeles, Calif. 7 Application May26, 1941, Serial No..395,'162

5 Claims.

My invention relates to improvements in air compressors and moreparticularly to that class of fluid compressors which is generallyalthough not exclusively employed for compressing air, gas and otherfluids in the various arts. While it is desirable to reduce the initialcost of construction as much aspossible consistent with strength,durability and effectiveness, it is a major object of the invention toproduce a maximumof fluid pressure with a minimum of power, thus tendingtowardjgreater economy and saving in expense of operation. Still furtherobjects are greater eificiency, durability and simplicity. To these endsmy invention comprises the features of construction and combination ofparts hereinafter'described and claimed. 1 V 1n the drawings formingpart of this specification, Fig. 1 is a vertical central section of myimproved fluid compressor which is of reciprocae ble piston and cylindertype, the piston being shown as it approaches fully fluid compressionposition near the inner end of its compression stroke, the broken lineposition indicating the outermost position assumed by the piston and itsactuated return check valve removed from the CompressomFig. 3 is a topplan ofthe fluid actuated return valve shown in Fig. 2, part of thestructure being broken away and in section showing the fluid ingressport openings; Fig. 4 is a bottom plan of the structure shown in Fig. 2;Fig. 5 is a transverse vertical section taken on the line 5-5 ofFig.'l'; Fig. 6 is a transverse horizontal section taken on line E5*'5of'Fig. 5; Fig. '7 is a diagram illustrating the increased ratio ofexhaust during the compression stroke,

and Fig. 8 is a vertical central section of an alternate constructionor" the upper end of the return check valve portion of my improved con--pressor.

In the drawings A indicates the cylinder, B the piston which isreciprocable in said cylinder, and C the crank case, of my improve-dcompressor. [0 is asuitable crank shaftjournaled in the horizontalsleeve l I eXtending laterally from the crank case, and having asuitable driving element such as pulley l2 on-its outer end and a crankl3 on its inner end. A suitable'pitman or connecting rod I4 is connectedto the crank. A toggle D composed of lower and upper arms I5 and I5flexed together by the pintle I! is connected by said pintle tothe freeend of the pitman. The lower extremity of the lower arm [5 of the toggleis journaledj to rock by the bearing I! on thelowerportion of the crankcase and the upper extremity of the upper arm Hi valve closed horizontallower end wall 25.

is journaled by the piston pin 19 in the piston B. As the crank isrevolved in the direction of the arrow shown in Fig. l, the piston andthe toggle are reciprocated from the full line position as the pistonapproaches fully compressed position to the broken line position atthe'lower end of the fluid intake stroke, as shown in Fig. l.

The cylinder is extended upwardly and increased in diameter to provide acylindrical valve chamber E, the latter being closed by an end coverplate 28. A return check valve of float piston type F reciprocablecoaxially with and of greater diameter than the diameter of pistonB inthe cylindrical valve chamber closes downwardly upon the annularoutwardly flaring seat 2|, the latter being arranged at the junctionbetween the compression cylinder and the wall of the valve chamberabovev and connecting with an annular outlet channel 42 adjacent theretoin the wall of the Cylindrical casing. The return check valve Fresembles a piston having a hollow cylindrical casing 22 closed at itsupper end by the horizontal end wall 23 and provided with fluid ingressports 24 in its side wall and a The ports 24 are adapted to registerwith fluid ingress openings such as 25 in the side wall of the valvechamber. The lower end wall of the fluid return check valve has acomparatively large annularfluid inlet centrally disposed and surroundedby a valve seat or orifice 21 with which an annular fluid admissioncheck valv '23 closes automatically to seal the passage through thefluid return check valve F during the compression stroke of piston B. Acompressed fluid outlet port 39 from the annular outlet channel 42,

through the wall of the cylinder, leads outwardly for transmitting thefluid which is compressed by piston B. Sealing rings 3! seated in thecylindrical surface ofthe return check valve F and a sealing cup Simadeout of lead or other suitable material in the return check valvecylinder are provided to maintain a tight working connection between thereturn check valve F and said cylinder. By making valve F larger indiameter than the main cylinder of the compressor a comparatively largevalve area is provided .iwhereby ayery slight reciprocable opening andclosing movement is necessary for discharging the compressed fluid andclosing the valve. In practice a compressor employing a fluidcompressing cylinder cf 6" internal diameter has required less than ainch opening movement. The fluid admission check valve 28 in the returncheck valve F has a central valve stem 35 which reciprocates freely in abridge support 36 integral with the side wall of the cylindrical floatreturn check valve structure. A helical spring 31 fitted over the bodyof the bridge support and below a washer 38 tends to hold the innerfluid ingress check valve 28 contained in the return check valve closedbut permits it to open freely during the intake stroke of piston B. Thusduring the intake stroke, the fluid medium to be compressed is drawnthroughthe openings 26, ports 24,and the-valvedorifice 2.1;;in 'tl1ereturn check valve F into the compression chamber within cylinder A.During this action the return check valve closes and is held closedautomatically upon its seat thus checking any returnof compressed fluidfrom duct 39. Thisplosing action of the return check valve isproducedpartly by the negative pressure or ;suction. ,createdzby theintake stroke of piston B but mainly by the pressure exerted bycompressed fluid previously admitted either byduct All, or;.ext ernalduct 45,

or .ho h i to th return ph ek va v cham a e v lveFther in- .D et hleadsupward y from -the circular fluid outlet wchannel A2 .,(see

Fig. :6) throughrthe .side wall ofand into the cy.-

IindricaLcha-mber above the return,check-.valve F and duct Al isconnected .witholltlet duct an eadsthroush ove rlat l intos d ha-m-.ber,. a suitabl vc ek .va ve A bein interposed to pre ent retu n ofompr s d .fi idp usly a mitted. ,In ,them fil ner stated the returniloatcheck valve Fishfild firmly losedvexeeptwhen id is comp essed Blindersuf ci nt pre sure h p e s onr ston Bit ve em h ent mat lq 'h tenden yof the returnv check valve.

Normal y h owe .atsur aee .of fluid admiss on. heck a re tliesonth plane.of the. lowe en fla sur ace eft eretu noheo valveF and ubstan ally n oe cano es ao i all w d beeen the piston endl we surfa el 'the r t rncheck va ve at the upperehdiotth ls oke of th H omp e o pi ton J3, whe ey substant ally-al of the m s dfillld.,and.iheato com r ss on -.ex1 e.le.d and cond ct d. away item t o nr s io ehamherdming eachoomp e n s koft eappa atus- .Dlu' hs c mpres ion h onenihe m eme of theretur uehe k.valvetis cushion d b th p essur o -e mpres ed.flnisl bov he eturn.check valve .aedthe retu neh k ve e iso i klv c os d .uponjth pi tonrversinat lthe ih ake t oke- Ihe eree ffect tr am-the ie llm c e,valvepverthat of th compression pis ncre s th o osil e fo impart .hvthfluiduno th velve. Due to th te aitlv' ly large ingress and e ress va aras pr v ded. .ver

' n h de ir d volu. etri c mpres io n re l h r e t dite for operation.The check valverof re ip hlepisto t e elose n i h lhvthex here sepressure resultin f h compres e .fi i .ro e erositlv and qu ck e necheemhic prevents the retur of. e sl eo-mpresse fiuis .intothe-com- 1sproducing improved results. in compressionland exhaust is produced byarproximately 200 degrees during which the exhaust period is prolonged,thus allowing substantially ;all of the compressed fluid to be expelled.Thus the check valve F coordinates with the toggle in This increasedratio ranging the axis of the crank in horizontal alignment with theupper end of the bottom link when s id linkan the compression pi t nlarein lower- .mostposition .,as.s l1 own in the. diagr am.' ,Ercm the dagramit,willhenoted that when theJhnk andpiston. revolve Irom lowermosttouppermost position the vconnectionbetween the connecting rod andtogglemoves throughypahout ZGU degrees of the arc throughwhichtheoranktravels, in

this. manner the. ompression stroke and. the exh st p riod ar incr asewhich Ji e dis in dvanta Also h radius .(ofaboutsleo deees d rin the,periodof int ke .is ma erially ducerlleavih a lo-n erperiod fo impression. D r n thep oh'eed exhaust, the power applied to thee nk ismatr al vredlleed bYthB u of the toggle over thatprovidedbyqa simple crankwithout a toggle.

In Fig- ,8, thelcylinderA is shovmih reased in d am t r at t ,upper end:50 above the return check valve F and the packin c p .5 I enla e .to.pr vi.de in .efiec supplemental piston or i rea e a ea a tin a a nsthe, e ur eh valve F to close theilattermore effectively by the inc easd -i r suppl ed .h h ompress ..fiuldin a ordanc with, the pat nt atutes,'Ijhave described the principles ,of operation of my inventio to eth .wth i e.vcohstrlicti whi hil n w co si e to pre en thehest emb d menthereoi, bu de re .to h ve .i underst od tha th structureshowniso-nlyjllustrativeand that the i en n. an he arried out by other we ansand ap l e t use o he than those. above set forth Withlnlthe s ope ofthefollowing l ms.

l. .A fluid mp esso ;h vin .a.o .in er formng a mpression .ehe her,..a ps on v.re procable in saidcoinpression chamber, said cylinder having areturn check valve chamberofincreased ame er and, provided ,anannular vave lseet between said compression and valve chambers. .a d out et due oc mpressed nnidfr m'sa d valve seat, a piston returncheck .valverecipcable insaid valve chamber in cooperation with said seat filhtrollin the,return .of compressed fluid into the.Qomplfession cha1nber, said pistonreturn check valve having, aninta-ke. duct through 'thewall ofsaidpylinder entering-the compression chamber forfluid to be compressed,an intake check valve controlling the fluid entering the compressionchamber through saidreturn-p eck valve, said returntcheck valve chamberhavingia co ne tio i h said outletduct .by which o mhressedfluid is tmlttedlintosa valv ham er above the return check valve tending to closesai etu n ch k valv L-u onre d sea :and a h ek i aid stimenti nedcon eonior preventing the return of compressed fluid admitted into said valvechamber.

2. A fluid compressor having a cylinder forming a compression chamber, apiston reciprocable in said compression chamber, said cylinder having anextension of increased diameter beyond the compression chamber providedwith an annular valve seat at its junction with said compression chamberhaving an outlet for compressed fluid, a return check valve reciprocablein said valve chamber, and adapted to close upon said seat, a connectionfor compressed fluid fromv the compression chamber controlled by saidreturn check valve and entering said return check valve chamber wherebyfluid compressed by the compression piston is adapted to urge the returncheck valve upon its seat, the' adjacent surfaces between thecompression piston and said return check. valve being arrangedsubstantially without clearance at the upper end of the compressionstroke of the compression piston, said return check valve having anintake duct through the wall of the cylinder and entering saidcompression chamber, an intake check valve in said duct maintainedclosed by compressed fluid in said'compression chamber and ing a returncheck valve chamber provided with an annular seat adjacent to saidcompression chamber, a return check valve reciprocable in said valvechamber and adapted to close upon said seat, an outlet connection forcompressed fluid from the compression chamber controlled by said returncheck valve and entering said return check valve chamber above saidreturn check valve whereby fluid compressed by said reciprocable pistonis adapted to urge' the return check valve upon its seat, a check insaid outlet connection for preventing return of compressed fluidadmitted into said valve chamber, the adjacent surfaces between thecompression piston and said return check valve being arrangedsubstantially without clearance at the upper end of the compressionstroke of said piston, and said return check valve having a valvedintake duct for the admission of fluid into said compression chamber,said duct being maintained closed by compressed fluid in saidcompression chamber and opened by negative pressure of fluid created bythe intake stroke of said-compression piston.

4. A fluid compressor having a cylinder form- 7 ing a compressionchamber, a piston reciprocable in said compression chamber, saidcylinder havvalve chamber and adapted to close upon said seat, an outletconnection for compressed fluid from the compression chamber controlledby said return check valve and entering said return check valve chamberabove said return check valve whereby fluid compressed by saidreciprocable piston is adapted to urge the return check valve upon itsseat to close said outlet connection, a check in said outlet connectionfor preventing the return of compressed fluid admitted into said valvechamber, and said return check valve having a valved intake duct for theadmission of fluid into said compression chamber, the valve in said ductbeing maintained closed by compressed fluid in said compression chamberand opened by negative pressure of fluid created by the intake stroke ofsaid compression piston.

5. A fluid compressor having a cylinder forming a compression chamber, apiston reciprocable in said compression chamber, said cylinder havin areturn check valve chamber provided with an annular seat adjacent tosaid compression'chamher, a return'check valve reciprocable in saidvalve chamber and adapted to close upon said seat, an

outlet connection for compressed fluid from t compression chambercontrolled by said return check valve and entering said return checkvalve chamber above said return check valve whereby fluid compressed bysaid reciprocable piston is adapted to urge the return check valve uponits seat, a check in said outlet connection for preventing return ofcompressed fluid admitted into said valve chamber, and said return checkvalve having a valved intake duct through the wall of the cylinder forthe admission of fluid into said compression chamber, said duct beingmaintained closed by compressed fluid in said compression chamber andopened by negative pressure of fluid created by the intake stroke ofsaid compression piston. r

- SELLERS E. JESSUP.

